Sequential turret tuner



Ci. 1948. J. 0, ELSEA 2,42 3

SEQUENTIAL TURRET TUNER Filed Aug. 14, 1946 Patented Oct. 26, 1948 SEQUENTIAL TURRET TUNER Jacob 0. Elsea, Koiromo, End, assignor to General Motors Corporation,

tion of Delaware Detroit, Mich, a corporaapplication August 14, 1946, Serial No. 690,457

3 Claims. 11

This application relates to manual or automatic indexing mechanism, and more particularly to mechanisms for tuning a radio receiver to a number of preselected stations, in sequence.

Radio receivers, especially those used in automobiles, must be capable of operation with a minimum of effort by the listener. A step in this direction is push button tuning in which a number of push buttons or levers, are available for selectively tuning the radio receiver to a desired station. By pushing one of these buttons or levers 1e various tuning elements of the receiver are forced into positions predetermined as being correct for station desired. By pushing another button the radio receiver is tuned to a second station. Thus by use of these push button assemblies, the operator of the set may select, and tune in any one of four or five present broadcasting stations. 4

Selective push button tuning, although possessing a number of advantages over dial tuning, still leaves something to be desired, particularly in automobile radios.

Push button tuners, by their very nature, must be located on or very near the radio cabinet, and the operator must visually select the button or iever he is to actuate.

In automobiles, the radio is usually located on or near the instrument panel. This is out of the normal field of. view of the driver, and remote from the steering wheel and the driver's normal position. A great need, therefore, arises for a tuning means which may be operated remotely and which requires no visual selection of the mechanism to be actuated. It is also very desirable that some means be provided for conveniently altering the stations preselected when the owner desires to change the combination of stations to be received.

It is therefore an object of this invention to provide an indexing device of improved design.

Another object of this invention is to provide an improved radio tuning device of the step by step type.

A further object of this invention is to provide a tuning device for radio receiving apparatus which is simple in'construction, inexpensive in cost, dependable in operation and of a size adapted to be positioned within a relatively restricted space.

Another object of this invention is to provide a sequential tuning device which may be manually or electrically operated.

A still further object of this invention is to prvide a sequential tuning device for permeability tuned radio sets.

With these and other objects in View, the embodiment of my invention'will best be understood by reference to the following specification and claims and the illustrations in the following drawings, in which:

Figure 1 is a view of the invention showing the turret in a tuned position.

Figure 2 illustrates the invention with the turrot in the retracted position.

Figure 3 is a detailed showing of the carnoperated indexing sear.

In the figures, 2 is the frame of the tuning assembly of a radio set, i is the solenoid coil which is energized to cause tuning. This solenoid for actuation of the turret, of course, may be replaced by manual or other mechanical equivalents without departing from the scope of my invention. 8 is a reciprocating slide assembly rotatably mounted thereon. it is a treadle bar which moves the tuning core l2 in coil i i to tune the set. This treadle bar, of course, may be connected to a variable condenser instead of tuning core 52 if capacity type tuning is preferred.

The turret plate it is mounted on the slide 3 by means of a spindle or pin it. This plate has projections 20 thereon to which are adjustably secured the tuning cams it by means of pins 22. These tuning cams may be present to tune the radio to the desired stations by adjusting screws 28. Rigidly mounted on the turret plate it and located in a fixed relationship to each of the cams 2d are projections 28. v

The reciprocating slide 8 is normally biased toward the retracted position by means of tension spring Bil. This spring is fastened at one end to a projection 32 on the slide and at the other end to a projectionti on the frame 2. Slide 8 has formed thereon a projection 36 to which the core 6 of the solenoid is attached. This slide also has an inwardly bent projection 38 cooperating with indexing pawl to. This pawl to is slidably supported on the slide a by means of pin 42 and slot it. This pawl is biased against one or more of the projections 28 by means of tension spring t6. This spring is capable of exerting an indexing force tangential to the turret or a locking force which is radial to the turret. When the pawl M1 is engaging the sear it or the pin 32 so it is capable of oscillatory motion only, the radial locking force exerted against two of the projections 28 predominates and the turret is locked in the indexed position. If the pawl it is released so it is capable of which carries the turret reciprocating movement, the tangential force on the turret will predominate and the turret will be indexed. The slide 8 also has mounted thereon a cam surface 50 against which the sear 48 is biased by means of spring 52. The sear 48 is moved out of engagement with the pawl 40 by means of this cam surface 50, thereby allowing the pawl to have reciprocating motion to index the turret.

The operation of this invention is as follows:

Referring to Figure 1. the slide and turret assembly is shown actuated to the left by means of energized solenoid 4. In this position the tuning cams '24 cooperate with surfacesoi the tuning treadle ill so as to tune the circuit to the desired station. The pawl 40 pivots about the pin 42 and is biased into engagement with two of the projections 28 to maintain the turret in the indexed position. When solenoid 4 is deenergized the spring 30 biases the slide 8 toward the retracted position. The sear 48 having dropped in behind the pawl 40 prevents the pawl from proceeding to the right with the slide and turret assembly. The pawl then rides up over the next projection 28 in clockwise sequence on the turret plate 18. As the assembly proceeds toward the retracted position, the sear .48 rides on cam 50 until the slide has almost reached the retracted position. The cam 50 at this point has moved the sear 48 sufliciently to clear the end of the pawl 40. The pawl 40 being biased by the spring 46, thereupon proceeds to the right, remaining in engagement with one of the'projections 28. This rotates the turret until the succeeding projection 28 engages the pawl. In this position the end of the pawl is in engagement with one of the projections 28 and is wedged between the next projection 28 and the projection 38 of the slide. The turret is now in the fully indexed position and ready for the next tuning stroke. The solenoid 4 is then reenergized and the entire assembly proceeds to the left toward the v tuned position with the sear 48 now biased into engagement with and riding on the side of the pawl 40. Upon almost reaching the tuned position the sear 48 drops in behind the pawl 40 and the assembly is again in the position shown in Figure l. s

From the description above, it may thus be seen that a succession of forces introduced either manually or electrically on the same element of a radio set, may be used to tune the set to several preselected frequencies in. sequence. Although the invention is specifically described for inductive 0r permeability tuning, it may be readily appreciated that the invention equally applies to capacitive tuning. A gang condenser could be driven by treadle bar In and the present invention vould be equally applicable to such a tuning mechanism.

It is to be understood also that although the invention has been described with specific referonce to a particular embodiment thereof, it is not to be so limited since changes and alterations therein may be made which are within the full intended scope of this invention as defined by the appended claims.

I claim:

1. In an indexing mechanism for sequential type turret radio tuners including; a reciprocating member carrying a rotatable turret with a plurality of tuning cams equidistantlyspaced on said turret, said turret also having a plurality of projections equidistantly spaced thereon, an indexing member slidably supported by said reciprocating member and biased into contact with said equidistantly spaced projections, said indexing member so positioned and arranged as to engage a projection on said turret to index the turret and to engage two of said projections to maintain said turret in the indexed position.

2. In an indexing mechanism for sequential type turret radio tuners including; a reciprocating member carrying a rotatable turret with a plurality of tuning cams equidistantly spaced on said turret, said turret also having a plurality of projections equidistantly spaced thereon, an indexing member slidably supported by said reciprocating member and biased into contact with said equidistantly spaced projections, said indexing member so arranged to engage a projection on said turret to index the turret and to engage two of said projections to maintain said turret in the indexed position, a sear rotatable in a plane normal to the direction of movement of said reciprocating member and biased into engagement with said indexing member, a cam on said reciprocating member engaging said sear to disengage it from said indexing member.

3. In an indexing mechanism for sequential type turret radio tuners including; a reciprocating member carrying a rotatable turret with a pinrality of tuning cams and a plurality of projections respectively equidistantly spaced thereon, an indexing member slidably supported by said reciprocating member and biased into contact with said equidistantly spaced projections, said indexing member exerting a radial force on said turret to maintain it in an indexed position and exerting a tangential force on said turret sufficient to overcome said radial forces and cause indexing of said turret when said turret is moved from the tuned to the fully retracted position.

. JACOB O. ELSEA.

REFERENCES CITED UNITED STATES PATENTS Name Date Noyes Nov. 6., 1917 Number Certificate of Correction l l Patent No. 2,452,443. v October 26, 1948.

JACOB O. ELSEA It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correctlon as follows:

Column 1, line 18, and column 2, line 31, for the word presen read preset;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 22nd day of February, A. D. 1949.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

